The present invention relates to systems used for protecting electronic, mechanical, hydraulic or other components from the effects of harsh environments that may exist in industrial facilities.
The importance of controlling and monitoring production processes using for example, electronic, mechanical, electromechanical, hydraulic devices and instrumentation requires that, at times, the electronic instrumentation be located in the production environment. This places the electronic instrumentation in surroundings that may be harsh and can often have a detrimental effect on the electronic components that such components may not be capable of withstanding. For example, electronic devices may be placed in a plant process environment that normally sustains saturation humidity that, over time, can severely damage and incapacitate the electronic components, if not properly protected.
Another problem occurs during plant cleaning or disinfection, which may require that the plant equipment used be cleaned with high pressure hot water. Water pressures greater than 600 psi may be used to plant clean equipment. Such cleaning can be detrimental to the electronic monitoring and control systems situated nearby. Such water pressures can easily penetrate most common rated electronic enclosures resulting in damage to the electronic circuitry contained within.
To overcome the problem, electronic components have been placed in hermetically sealed chambers that are designed to be waterproof. This technique is described in U.S. Pat. No. 6,075,204 to Celauro et al. This waterproof enclosure has proven successful under severely harsh conditions by preventing condensation from forming inside the enclosure as the outside temperature decreases, thereby eliminating damage to the electronics within. However, this system does not make a direct provision for the hermetically isolated satellite sensors connected to the system. Thus, the sensors are still subjected to the same harsh environment, unless the sensors are independently purged with a dry gas.
U.S. Pat. No. 5,603,892 to Grilletto et al. provides a gas purged electronics enclosure in which a control system is used to open and close valves to purge a contaminant-free gas through the electronics enclosure. In addition, a getter material is used as a scavenger to ensure the removal of contaminants. This patent describes a system that has only one enclosure for housing electronic components.
While purge systems are known, the prior art does not provide a suitable and economical solution for protecting electronic and other devices that may be located in various places throughout a process environment and which may be interconnected. What is needed is an integrated system that is capable of protecting these multiple interconnected devices.